Hi there,

I'm not completely positive what language version of the program you're using, but generally in this generation of the program the free codec activations are sorted out automatically during the online registration procedure. So, register online through the program, if you haven't done so yet. If that didn't work out, for whatever reason, try the following: Go to the "File" menu and initiate a MPEG-4 file export via the appropriate export option. The MPEG-4 activation dialog will come up if the codec hasn't been activated yet. If your computer is connected to the Internet, choose the direct online activation option and follow the on-screen instructions. If you're working on an offline machine or if you're experiencing problems with the online activation (e.g. router/firewall related), use an offline activation option and/or get in touch with Magix support/sales to help you out.

I hope this helps!